Clinical outcomes of perforator-based propeller flaps versus free flaps in soft tissue reconstruction for lower leg and foot trauma: a retrospective single-centre comparative study.

BACKGROUND: The efficacy and safety of perforator-based propeller flaps (PPF) versus free flaps (FF) in traumatic lower leg and foot reconstructions are debated. PPFs are perceived as simpler due to advantages like avoiding microsurgery, but concerns about complications, such as flap congestion and necrosis, persist. This study aimed to compare outcomes of PPF and FF in trauma-related distal lower extremity soft tissue reconstruction. METHODS: We retrospectively studied 38 flaps in 33 patients who underwent lower leg and foot soft tissue reconstruction due to trauma at our hospital from 2015 until 2022. Flap-related outcomes and complications were compared between the PPF group (18 flaps in 15 patients) and the FF group (20 flaps in 18 patients). These included complete and partial flap necrosis, venous congestion, delayed osteomyelitis, and the coverage failure rate, defined as the need for secondary flaps due to flap necrosis. RESULTS: The coverage failure rate was 22% in the PPF group and 5% in the FF group, with complete necrosis observed in 11% of the PPF group and 5% of the FF group, and partial necrosis in 39% of the PPF group and 10% of the FF group, indicating no significant difference between the two groups. However, venous congestion was significantly higher in 72% of the PPF group compared to 10% of the FF group. Four PPFs and one FF required FF reconstruction due to implant/fracture exposure from necrosis. Additionally, four PPFs developed delayed osteomyelitis post-healing, requiring reconstruction using free vascularized bone graft in three out of four cases. CONCLUSIONS: Flap necrosis in traumatic lower-leg defects can lead to reconstructive failure, exposing implants or fractures and potentially causing catastrophic outcomes like osteomyelitis, jeopardizing limb salvage. Surgeons should be cautious about deeming PPFs as straightforward and microsurgery-free procedures, given the increased complication rates compared to FFs in traumatic reconstruction. DATA ACCESS STATEMENT: The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.

A simple free flap strategy using end-to-side anastomosis to the main vessels in injured extremity.

Background: During free flap surgery, the surgeon sometimes encounters problems with anastomosis such as intractable arterial spasms or vessel size discrepancy in venous anastomoses. End-to-side (ETS) anastomosis has the advantages of limited chance of vessel spasm and easy handling by adjusting for vessel size discrepancy. We introduced the arterial and venous end-to-side anastomosis (AV-ETS) strategy, which is based on the ETS anastomosis to the main artery and accompanying veins, to avoid intraoperative anastomotic problems when creating a free flap. The aim of this study was to compare flap outcomes and intraoperative anastomotic problems before and after introduction of the AV-ETS strategy in extremity free flap surgery. Materials and methods: We retrospectively examined 72 consecutive extremity free flaps. Before introducing the AV-ETS strategy, we used the conventional strategy in which the recipient artery was selected according to the number of the remaining main artery and the anastomosis technique was flexibly changed, although the end-to-end (ETE) technique was used in most cases. Results: The conventional group had 18 flaps and the AV-ETS group had 54 flaps. The rate of flap survival did not differ between these groups, and there were no cases of flap failure after the introduction of the AV-ETS strategy. The AV-ETS group had significantly fewer flaps that required a change in preoperative planning for the recipient artery or anastomotic site of the artery. Conclusions: The AV-ETS strategy may facilitate reliable preoperative planning and the performance of stable free flap surgery without requiring a flexible response during surgery.

Efficacy of the microscopic parachute end-to-side technique for creating large-to-small venous anastomoses in free flaps in the extremities.

Purpose: The availability of reliable and suitably sized veins is limited for creating free flaps to treat severe trauma and infection, and it is important to manage vessel size discrepancy between the recipient and flap veins. We evaluated the clinical outcomes of free flaps with large-to-small venous end-to-side (ETS) anastomoses using the microscopic parachute end-to-side (MPETS) anastomosis in soft tissue defects in the extremities. This procedure comprises mainly a wide-slit venotomy and parachute procedure at the heel. Methods: We examined 24 free flaps in 23 patients given a large-to-small venous anastomosis using the MPETS technique. Patient demographics, details of vessel anastomoses, and flap outcomes and complications were obtained from medical records. Results: Two veins were anastomosed in six flaps. Thirty anastomosed veins were assessed, and 24 deep veins, all of which accompanied main arteries, were chosen as recipient veins. The mean diameters were 1.5 mm in the recipient veins and 2.7 mm in the flap veins, and the mean vessel size discrepancy was 1.8-fold (range 1.3-3.3 fold). Because of the presence of venous valves at the anastomotic site, trimming of venous cusps was performed in six veins. All flaps survived, though one venous thrombosis occurred because of pedicle kinking in a case with a short pedicle. Conclusions: The MPETS technique is simple, reliable, and useful for performing various types of venous anastomoses regardless of a vessel size discrepancy and the presence of a venous valve. This may be a good option for large-to-small venous anastomosis in free flaps.

In vivo monitoring of intravenously injected gold nanorods using near-infrared light.

Gold nanorods showing surface plasmon (SP) bands in the near-IR region are used as bioimaging probes that respond to near-IR light in mice. The SP bands of intravenously injected polyethylene glycol-modified gold nanorods are directly monitored from the mouse abdomen by using a spectrophotometer equipped with an integrating sphere. The absorbance at 900 nm from the gold nanorods immediately increases after injection and reaches a plateau. The injection of phosphatidylcholine-modified gold nanorods also increases the absorbance at 900 nm, but the absorbance decreases single exponentially with a 1.3-min half-life. In vivo spectral changes of gold nanorods depend on the surface characteristics, and can be observed in real time using simple spectroscopic measurements.